title: 'Plan of the day' adaptive radiotherapy for bladder cancer using helical tomotherapy.
abstract: OBJECTIVE
  This study assessed the potential of tomotherapy based Image Guided Radiotherapy (IGRT) to increase the accuracy of bladder irradiation using a 'plan of the day' adaptive radiotherapy (ART) technique.
  
  
  METHODS
  Ten patients with muscle invasive bladder cancer underwent bladder preservation with trimodality therapy in an ongoing trial. All patients received 64 Gy/32# to the whole bladder and seven of them received a boost of 68 Gy/32# to the tumour bed. The ART technique entailed the generation of six IMRT plans for each patient, using six isotropic PTVs of 5-30 mm applied to the bladder volume (CTV) to generate the PTVs. Megavoltage CT (MVCT) imaging was done to correct positioning errors and choose the 'plan of the day'.
  
  
  RESULTS
  Post treatment MVCT scans (315 scans) were used to generate multiple anisotropic PTVs for three hypothetical scenarios. Overall, coverage of anterior and superior walls required larger margins than other walls. Maximum geographical miss, in spite of IGRT, was noted for the superior (13.8%) and anterior walls (10.3%).
  
  
  CONCLUSIONS
  Plan of the day ART is a feasible and promising technique for optimal treatment and dose escalation in bladder cancer.
authors.affiliation: Department of Radiation Oncology, Tata Memorial Centre, Mumbai, India. vmurthy@actrec.gov.in
authors.forename: Vedang
authors.initials: V
authors.lastname: Murthy
authors.forename: Zubin
authors.initials: Z
authors.lastname: Master
authors.forename: Pranjal
authors.initials: P
authors.lastname: Adurkar
authors.forename: Indranil
authors.initials: I
authors.lastname: Mallick
authors.forename: Umesh
authors.initials: U
authors.lastname: Mahantshetty
authors.forename: Ganesh
authors.initials: G
authors.lastname: Bakshi
authors.forename: Hemant
authors.initials: H
authors.lastname: Tongaonkar
authors.forename: Shyamkishore
authors.initials: S
authors.lastname: Shrivastava
mesh_terms: D000328:Adult; D000368:Aged; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D010865:Pilot Projects; D011857:Radiographic Image Interpretation, Computer-Assisted; D015641:Radiography, Interventional; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome; D001749:Urinary Bladder Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*